1. Technical Field
The present invention relates to a fuel cell system, and more particularly, to a fuel cell system using a portable butane fuel.
2. Related Art
In general, a fuel cell is a power generating system that directly transforms chemical energy into electric energy by an electrochemical reaction between hydrogen and oxygen. In supplying hydrogen to a fuel cell system, pure hydrogen can be directly used, or methanol, ethanol, natural gas or the like can be reformed. Furthermore, in supplying oxygen to the fuel cell system, pure oxygen can be directly used, or oxygen contained in air can be supplied by an air pump or the like.
Meanwhile, the fuel cells are classified into: a polymer electrolyte membrane fuel cell (PEMFC) and a direct methanol fuel cell (DMFC), which operate at room temperature or a temperature of less than 100° C.; a phosphoric acid fuel cell (PAFC) which operates at a temperature of 150° C.˜200° C.; a molten carbon fuel cell (MCFC) which operates at a temperature of 600° C.˜700° C.; a solid oxide fuel cell (SOFC) which operates at a high temperature of more than 1000° C.; and so on. These fuel cells operate on basically the same principle, but they are different in the type of used fuel, catalyst, electrolyte, and so on.
Among the fuel cells, the polymer electrolyte membrane fuel cell (PEMFC) uses hydrogen obtained by reforming methanol, ethanol, natural gas, etc., and has advantages as compared with other types of fuel cells in that its output performance is very excellent, its operation temperature is low, and its start and response are quickly performed. Thus, the PEMFC can be widely used as a distributed power source for a house and a public building, a small portable power source for a portable electronic apparatus, etc., as well as a transportable power source for a vehicle.
In a polymer electrolyte membrane fuel cell system, the fuel is a material such as methanol, ethanol, natural gas and the like, which can be reformed to produce hydrogen. Furthermore, a mixture of butane fuel and water is called mixed fuel.
The polymer electrolyte membrane fuel cell basically includes a fuel container for storing fuel, a reformer for reforming the fuel to produce hydrogen, and an electric generator for generating predetermined voltage and current by electrochemical reaction between hydrogen and oxygen.
When the fuel is supplied to the reformer, fuel pumps requiring a separate power source are needed. Furthermore, the reformer is supplied with oxygen by an air feeder requiring a separate power source, so that the fuel is burned. In the meantime, water produced in the electric generator is cooled and condensed in a condenser. In order to facilitate the cooling effect of the condenser, a cooler requiring a separate power source is needed.
Thus, while operating such a polymer electrolyte membrane fuel cell system, units requiring separate power sources are needed. Consequently, power for driving the fuel cells is additionally needed, thereby deteriorating efficient operation of the fuel cell.